A radical cyclisation based cyclopentenone annulation of allyl alcohols
摘要:
A four-step cyclopentenone annulation reaction of allylic alcohols employing a 5-exo-trig radical cyclisation reaction of mixed allyl methyl ketals of bromoacetone as the key step is described. The annulated product 1215 obtained from 2.3-dimethylcyclohexenol has been further elaborated into (+/-)-epibakkenolides employing a 5-exo-dig radical cylisation reaction based alpha-spiro-beta-methvlene-gamma-butyrolactone annulation methodology. (C) 2003 Elsevier Ltd. All rights reserved.